Pig iron is the intermediate product of the iron industry. Crude iron as first obtained from the melting furnace, in the form of a block of oblong. Iron pigs have very high carbon content, typically 3.8-4.7%, along with silica and other constituents of waste, which make it very fragile, and not as useful as materials except for limited applications. Pig iron is made by smelting iron ore into ingots that can be transported from an impure high-content iron in a blast furnace as a material for further processing steps. The traditional form of mold used for pig iron ingots is a branched structure that forms in the sand, with many individual ingots at right angles to the center channel or sprinters, resembling pig litter which is fed by pigs.. When the metal has cooled and hardened, the smaller ingot (pig ) just broke from the pig ( pig ), hence my pig iron name. Since pig iron is intended for re-melting, uneven bar sizes and small sand inclusions only cause unnecessary problems given the ease of casting and handling.
Video Pig iron
Histori
Melting and wrought-iron production are known in ancient Europe and the Middle East, but iron is produced in bloom by direct reduction. Rough iron was not produced in Europe before the Middle Ages. The Chinese also made pig iron by the later Zhou Dynasty (which ended in 256 BC). Furnaces such as Lapphyttan in Sweden probably date from the 12th century; and some in Mark, Westfalen, Germany 13th. It remains to be determined whether this northern European development comes from the Chinese. Wagner has postulated possible relationships through Persian contacts with China along the Silk Road and Viking contacts with Persia, but there is a chronological gap between the Viking and Lapphyttan periods.
The transition of the iron phase to liquid in the furnace is a phenomenon that is avoided, because the decarburization of pig iron into steel is a very tedious process using medieval technology.
Maps Pig iron
Usage
Traditionally, pig iron is processed into wrought iron in wrought iron, then puddling furnace, and recently become steel. In this process, the crude iron is melted and a strong air current is directed upwards when stirred or agitated. This causes dissolved impurities (such as silicon) to be thoroughly oxidized. The intermediate products of puddling are known as enhanced pig iron, finers metal, or refined iron.
Pig iron can also be used to produce gray iron. This is achieved by recycling the pig iron, often along with large amounts of steel and scrap metal, removing unwanted contaminants, adding alloys, and adjusting the carbon content. Some pig iron grades are suitable for producing ductile iron. These are pure iron pigs of high purity and depending on the level of ductile iron produced, these pig iron may be low in silicon, manganese, sulfur and phosphorus elements. This type of pig iron is used to melt all elements (except carbon) in ductile iron loading which can be harmful to ductile iron processes.
The modern usage
Until now, pig iron is usually poured straight out from the bottom of the blast furnace through a manger into a spoon car to be transferred to the steel mill in its most liquid form; in this state, the pig iron is referred to as hot metal . The hot metal is then poured into a steelmaking vessel to produce steel, usually an electric arc furnace, an induction furnace or a basic oxygen furnace, in which excess carbon is burned and the alloy composition is controlled. Prior processes for this include finishing forge, powder furnace, Bessemer process, and open fireplace furnace.
Modern steel plants and direct reduction iron plants transfer the molten iron to spoons for immediate use in steelmaking furnaces or dispose of them into pigs on pigskin machines for reuse or resale. Modern pig-casting machines produce pigs, which break into smaller pigs 4-10 kg when removed.
See also
- Hot Metal Bridge
References
Source of the article : Wikipedia
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